Tin or tin alloy electroplating solution

ABSTRACT

An additive obtained from the reaction product obtained by reacting glutaraldehyde and at least one type of compound selected from hydrocarbon compounds containing a hydroxyl group, and at least one type of compound selected from amine compounds, as well as a tin or tin alloy plating solution containing this additive.

This application is a Divisional of U.S. Non-Provisional applicationSer. No. 13/094,092, filed Apr. 26, 2011 which application is aContinuation of U.S. Non-Provisional application Ser. No. 12/150,233,filed Apr. 24, 2008 and now granted U.S. Pat. No. 7,931,793, whichpatent claims priority of Japanese Patent Application No. 2007-114798,filed Apr. 24, 2007, the entire contents of which applications areincorporated herein by reference.

The present invention relates to a tin or tin alloy electroplatingsolution and to an additive. In further detail, the present inventionrelates to a novel additive for an acidic-based electrolytic tin or tinalloy plating solution that is particularly preferable for use withbarrel plating, and to a tin or tin alloy plating solution using thisadditive.

Tin and tin alloy plating is used in electronic components that requireelectrical connections, such as chip components, lead frames, printboard circuits, and the like, because of the excellent connectingproperties, low cost, electrical properties, and soldering properties.

Surface mounting chip components such as resistors and capacitors, andthe like, which are used in surface mounting are generally tin plated onthe electrodes using a barrel plating method in order to providesoldering properties to the electrodes. Problems are known with thebarrel plating method where the chip components will congregatetogether, or in other words the chip components will adhere to oneanother. In order to prevent this congregation, a complexing agent isadded to the tin plating solution and therefore the tin plating solutionis slightly acidic (pH between 3 and 5) (for example see Japaneseunexamined patent application 2001-24093). However, the complexingagents used in tin plating solutions are generally compounds which donot naturally decompose, and therefore are a burden on the environmentunless appropriate waste water treatment is performed. Therefore, wastewater treatment of the plating solution and the wash water which containthe complexing agent is complicated and expensive, so there is demandfor a tin plating solution which does not contain a complexing agent.

Furthermore, strongly acidic tin plating solutions have been proposedsuch as those containing an aromatic aldehyde and a low-level aliphaticaldehyde in a tin plating solution that uses an alkanesulfonic acid (forexample see Japanese unexamined patent application S61-223193), thoseusing the reaction products of acetaldehyde or an aldol condensate ofacetaldehyde and a compound selected from a group consisting of ammonia,non-cyclic ketones, aliphatic amines, aliphatic amides, aliphatic aminoacids, and aliphatic hydrazine compounds (for example see Japaneseunexamined patent application H2-232389), and those containing anaromatic aldehyde and an N-substituted unsaturated aliphatic amidecompound (for example see Japanese unexamined patent applicationH4-83894). However, there are no products that are effective atpreventing chip components from adhering together when using a barrelplating method.

An objective of the present invention is to provide an electrolytic tinor tin alloy plating solution and additive that can resolve theaforementioned problems, has little burden on the environment, does notrequire complicated waste water treatment, suppresses the chipcomponents from adhering together when using a barrel plating method,and which can perform uniform tin or tin alloy plating.

As a result of diligent investigations to resolve the aforementionedproblems, the present inventors have discovered that the aforementionedobjectives can be achieved by using a compound obtained by reactingspecific components in a tin or tin alloy plating solution, and havethus achieved the present invention. In other words, the presentinvention is an additive that provides a tin or tin alloy platingsolution, comprising:

(1) a reaction product obtained by reacting glutaraldehyde and at leastone type of compound selected from hydrocarbon compounds containing ahydroxyl group in the presence of an acid; and

(2) at least one type of compound selected from amine compounds.

Furthermore, the present invention is a tin or tin alloy electroplatingsolution that provides a plating solution comprising:

(1) stannous ion;

(2) acidic component;

(3) reaction product obtained by reacting at least one type of compoundselected from amine compounds with the product obtained by reactingglutaraldehyde and at least one type of compound selected fromhydrocarbon compounds containing a hydroxyl group in the presence of anacid; and(4) a nonionic surfactant.

Furthermore, the present invention provides an additive for a tin or tinalloy electroplating solution, comprising the product obtained byreacting glutaraldehyde and at least one type of compound selected fromhydrocarbon compounds containing a hydroxyl group in the presence of anacid and at least one type of compound selected from amine compounds.

Furthermore, the present invention is a manufacturing method of anadditive for a tin or tin alloy electroplating solution that provides amanufacturing method for an additive comprising:

(1) a step of reacting glutaraldehyde and at least one type of compoundselected from hydrocarbon compounds containing a hydroxyl group in thepresence of an acid; and

(2) a step of adding at least one type of compound selected from aminecompounds to the reaction solution.

The present invention also provides a manufacturing method for an acidictin or tin alloy electroplating solution, wherein the aforementionedadditive is added to an acidic solution containing stannous ion and anacid component.

Using the tin plating solution of the present invention can suppress theobjects for plating from adhering together when barrel plating, and canprovide a plating film which has excellent soldering properties withoutusing a complexing agent which is a heavy burden on the environment andrequires complicated waste water treatment. Furthermore, theaforementioned tin plating solution can be provided by using theadditive for a tin plating solution of the present invention.

The present invention will be described below in detail. The tin platingsolution of the present invention comprises the reaction product of theadditive (A) shown below, stannous ions, an acid component, andoptionally other metal ions, optionally a nonionic surfactant, andoptionally an antioxidant.

The abbreviations used throughout this specification have the followingmeaning unless otherwise designated.

g=gram; mg=milligram; ° C.=degrees Celsius; min=minute; m=meter;cm=centimeter; L=liter; mL=milliliter; A=Ampere; dm²=square decimeter.All numerical ranges are inclusive and may be combined in any order. Theterms “plating solution” and “plating bath” used throughout thisspecification are used interchangeably and have the same meaning. Theterms “alkane” and “alkanol” refer to straight chain or branched chainalkanes or alkanols. In this specification, the phrase “solution of ahydrocarbon compound containing a hydroxyl group” refers to mixtures ofsolvent and a hydrocarbon compound containing a hydroxyl group or to thehydrocarbon compound containing a hydroxyl group itself.

Additive (A) for the tin or tin alloy electroplating solution of thepresent invention is a composition that comprises the reaction productobtained by reacting glutaraldehyde and at least one type of compoundselected from hydrocarbon compounds containing a hydroxyl group in thepresence of an acid, and at least one type of compound selected fromamine compounds.

Hydrocarbon compounds containing a hydroxyl group refers to hydrocarboncompounds which have one or more hydroxyl groups. Preferable hydrocarboncompounds containing a hydroxyl group are straight chain, branched, orcyclical substituted or unsubstituted compounds with between 1 and 10carbons, more preferably between 1 and 6 carbons, and even morepreferably between 1 and 3 carbons which have between 1 and 6 hydroxylgroups, more preferably with between 1 and 3 hydroxyl groups, andexamples include monohydric or polyhydric alcohols and sugars, and thelike. Specific examples of hydrocarbon compounds containing a hydroxylgroup are monoalcohol compounds, glycol compounds, glycerin compounds,sugars, and sugar alcohols, and the like. Examples of monoalcoholcompounds include methanol, ethanol, propanol, isopropanol, and phenol,and the like. Examples of glycol compounds include ethylene glycol,1,3-propylene glycol, 1,2-propylene glycol, 1,2-butylene glycol,1,3-butylene glycol, 1,4-butylene glycol, 1,2-isobutylene glycol,1,3-isobutylene glycol, and the like. An example of a sugar is glucose,or the like. An example of a sugar alcohol is sorbitol, or the like.Preferable hydrocarbon compounds containing a hydroxyl group of thepresent invention are ethylene glycol, 1,2-propylene glycol, and1,3-propylene glycol.

The reaction between the aforementioned hydrocarbon compound containinga hydroxyl group and glutaraldehyde, for instance, is performed as aresult of mixing glutaraldehyde with at least one type of hydrocarboncompound containing a hydroxyl group in the presence of an acid. Thereaction can be performed by adding and blending glutaraldehyde with ahydrocarbon compound containing a hydroxyl group in a solvent, or byblending without using a solvent. Furthermore, blending can be performedafter diluting either one or both of the hydrocarbon compoundscontaining a hydroxyl group and the glutaraldehyde with a solvent. Thesolvent can be a polar solvent such as water or an alcohol such asmethanol or ethanol, or the like. The glutaraldehyde is blended with anequivalent molar amount, or less than an equivalent molar amount of thehydrocarbon compound containing a hydroxyl group. The reaction time ispreferably maintained between 0.5 hours and 3 hours by maintaining thesolution temperature between 30° C. and 70° C.

The acid is provided to the reaction solution by adding an acidiccomponent, and for instance, can be provided by adding an acidiccomponent to the solution of a hydrocarbon compound containing ahydroxyl group, or by adding an acidic component to a mixture ofglutaraldehyde and a hydrocarbon compound containing a hydroxyl group.Examples of the acidic component include sulfuric acid, hydrochloricacid, alkanesulfonic acid, and alkanolsulfonic acid, and the like.

Examples of the amine compound include ammonia, ethylenediamine,diethylenetriamine, n-propylamine, 1,2-propanediamine,1,3-propanediamine, dimethylamine, hexamethylenetetramine,tetraethylenepentamine, triethanolamine, hexamethylenediamine,polyoxyalkylamine, polyoxyalkyldiamine, polyoxyalkyltriamine, and thelike. A composition that contains a polyoxyalkylamine or apolyoxyalkyldiamine and the reaction products of glutaraldehyde and1,2-propylene glycol or 1,3-propylene glycol is preferable. Particularlypreferable amine compounds are those selected from the compoundsexpressed by Formula (I).X₁—CH(X₂)—R—O—CH(Y₁)—NH₂  (I)

In the aforementioned formula, X₁ is a hydrogen atom or an amino group,X₂ is a hydrogen atom or a C₁-C₃ alkyl group, or an amino group, Y₁ is ahydrogen atom or a C₁-C₃ alkyl group, or an amino group, and R is apolyoxyalkyl group. For example, R is —O—CH₂—, —O—CH₂—CH₂—, —O—CH(CH₃)—,—O—(CH₂)₃—, —O—CH(CH₃)—CH₂— or —O—CH₂—CH(CH₃)—.

The target Additive (A) can be obtained by adding at one time and mixingthe amine compound selected above to the reaction solution of theglutaraldehyde and the hydrocarbon compound containing a hydroxyl group,in a quantity such that the solution obtained will be alkaline with a pHof 9 or higher, preferably between 9.5 and 12.0. Furthermore, the amountof amine compound added is preferably an equivalent to or higher thanthe molar amount of the glutaraldehyde for the case where a monoaminecompound is used, and is preferably one half or more of an equivalentmolar amount of the glutaraldehyde for the case where a diamine compoundis used, and is preferably one third or more of an equivalent molaramount of the glutaraldehyde for the case where a triamine compound isused.

For instance, the specific method for manufacturing the additive (A) ofthe present invention is a method comprising:

(1) a step of preparing at least one type of hydrocarbon compoundcontaining a hydroxyl group;

(2) a step of obtaining an acidic solution of a hydrocarbon compoundcontaining a hydroxyl group by adding an acidic component to theaforementioned solution of a hydrocarbon compound containing a hydroxylgroup, and then mixing for between 5 minutes and 15 minutes at a liquidtemperature of between 30° C. and 70° C., preferably between 40° C. and50° C.;(3) a step of obtaining a reaction product's solution by adding anamount of glutaraldehyde no more than the equivalent molar amount ofhydrocarbon containing a hydroxyl group in the acidic solution ofhydrocarbon compound containing a hydroxyl group obtained, and thenmixing at a solution temperature between 30° C. and 70° C., preferablybetween 40° C. and 50° C., for between 30 minutes and 3 hours,preferably between 45 minutes and 70 minutes;(4) optionally, a step of bringing the liquid temperature of thereaction product solution to 40° C. or less, preferably between 20° C.and 25° C.;(5) optionally, a step of adding a nonionic surfactant; and(6) a step of adding to the solution that is obtained at least one typeof amine compound in an amount no less than the equivalent molar amount(for the case of a monoamine compound) of glutaraldehyde.

Examples of the nonionic surfactant that can be used in step (5) includepolyoxyethylene lauryl ether, polyethylene glycol, polyoxyethylene alkylether, polyoxyethylene polyoxypropylene glycol, polyoxyethylenenonylphenyl ether, polyoxyethylene polyoxypropylene alkylamine, andpolyoxyethylene adducts of ethylenediamines, and the like, butpolyoxyethylene monoalkyl ether or phenolethoxylate are preferable.These surfactants can be commercially procured, and can be purchasedfrom ADEKA Corporation as a product named Adekatol™ PC-8. These nonionicsurfactants may be used independently or as a mixture of two or more.

The amount of additive (A) of the present invention that is added to 1 Lof the tin plating solution is an amount of additive (A) that containsbetween 0.5 and 50 g, preferably between 2 and 20 g of the reactionproducts of glutaraldehyde and a hydrocarbon compound containing ahydroxyl group. The reaction product's solution obtained can be added tothe tin plating solution as is, or can be used after purifying byfiltering or distilling, or the like.

Additive (A) of the present invention is thought to form additivereaction products which are useful in tin or tin alloy plating solutionsbecause the amine compounds react with the reaction products of theglutaraldehyde and the hydrocarbon compound containing a hydroxyl groupin the additive (A) by coming in contact with an acidic solution. If thereaction product of glutaraldehyde and at least one type of compoundselected from hydrocarbon compounds containing a hydroxyl group and atleast one type of compound selected from amine compounds are addedindividually to an acidic solution without mixing, the desired reactionwill not occur and additive reaction products which are useful in a tinor tin alloy plating solution will not be formed. Theoretically,restricting is not preferable, but the reaction between at least onetype of compound selected from amine compounds and the reaction productsbetween glutaraldehyde and at least one type of compound selected fromhydrocarbon compounds containing a hydroxyl group is thought to proceedwhen the additive (A) which is alkaline moves from being alkalinethrough the neutral region and becomes acidic, and is thought that thereaction will not proceed when the pH in the acidic solution is 1 orhigher. Therefore, the alkaline additive composition containing an aminecompound and the reaction products of glutaraldehyde and a hydrocarboncompound containing a hydroxyl group must come in contact with an acidicsolution and become an acidic solution for a short period of time.Additive (A) of the present invention can be brought into contact with asufficient quantity of acidic solution to maintain acidity, and afterthe additive reaction products are formed, be added to a tin or tinalloy plating solution, or additive (A) of the present invention can bedirectly added to an acidic tin or tin alloy plating solution.

The stannous ion that can be used with the present invention is abivalent ion. Various types of compounds may be used if they are able toprovide this type of ion in the plating bath. Examples include thestannous salt of inorganic acids such as sulfuric acid and hydrochloricacid, as well as organic acids such as methanesulfonic acid, citricacid, and malic acid, or the like. Preferable sources of stannous ionsinclude, for example, the tin salt of an acid selected from theaforementioned organic acids. The tin salts of substituted orunsubstituted alkanesulfonic acid or alkanolsulfonic acid are morepreferable, including compounds selected from the stannous salt ofalkanesulfonic acids or alkanolsulfonic acids such as methanesulfonicacid, ethanesulfonic acid, propanesulfonic acid,2-hydroxyethane-1-sulfonic acid, 2-hydroxypropane-1-sulfonic acid, or1-hydroxypropane-2-sulfonic acid, and the like. Generally, the use oftin salts of organic acids that are used in commonly known platingsolutions is preferable. These stannous ions may be used independentlyor as a mixture of two or more. The quantity of stannous ion in theplating solution is, for example, 10 g/L or more and 100 g/L or less,preferably 16 g/L or more and 70 g/L or less, and more preferably 20 g/Lor more and 30 g/L or less of tin methanesulfate.

The acid component of the present invention can be either an inorganicacid or an organic acid. Examples of inorganic acids include sulfuricacid and hydrochloric acid, and the like. The organic acids can be anacid selected from an alkanesulfonic acid or an alkanolsulfonic acid. Apreferable alkanesulfonic acid or alkanolsulfonic acid can be an acidwhich can be used with the aforementioned tin salts, and methanesulfonicacid is more preferable. These acid components may be used independentlyor as a mixture of two or more. The quantity of acid component in theplating bath solution is stoichiometrically equal to at least the samenumber of equivalents as bivalent tin ion present in the plating bath.For example, the quantity of free acid in the plating bath should be 15mL/L or more and 500 mL/L or less, preferably 20 mL/L or more and 150mL/L or less, and more preferably between 50 mL/L and 100 mL/L.

A surfactant may optionally be added to the plating solution of thepresent invention. The surfactant may be any type of surfactant, butnonionic surfactants are appropriate. Examples of preferable nonionicsurfactants include polyoxyethylene lauryl ether, polyethylene glycol,polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene glycol,polyoxyethylene nonylphenyl ether, polyoxyethylene polyoxypropylenealkylamine, and polyoxyethylene adducts of ethylenediamines, and thelike, but polyoxyethylene monoalkyl ether or phenolethoxylate arepreferable. These surfactants can be commercially procured, and can bepurchased from ADEKA Corporation as a product named Adekatol™ PC-8.

An appropriate concentration of surfactant in the plating bath, is forinstance, 0.01 g/L or more and 50 g/L or less, preferably 0.05 g/L ormore and 20 g/L or less, more preferably 0.1 g/L or more and 15 g/L orless.

Metal ions other than tin can optionally be added to the platingsolution of the present invention. These metal ions include the ions oflead, tin, silver, bismuth, and thallium, and the like. Various types ofcompounds may be used if they are able to provide this type of ion inthe plating bath. Examples include the lower valence metal salt ofsulfuric acid, hydrochloric acid, and organic acids such as methanesulfonic acid, citric acid, and malic acid, or the like. These metalions may be used independently or as a mixture of two or more.

The amount of metal ions other than tin in the plating solution, is forexample, 0 g/L or more, and 30 g/L or less, preferably 0 g/L or more and15 g/L or less.

An antioxidant may be arbitrarily used in the plating solution of thepresent invention. The antioxidant is used to prevent oxidation frombivalent tin to quadrivalent tin, and, for instance, hydroquinone,catechol, resorcin, phloroglucin, pyrogallol, hydroquinonesulfonic acidand salts thereof can be used. These antioxidants may be usedindependently or as a mixture of two or more.

An appropriate concentration of antioxidant in the plating bath is, forinstance, 0.01 g/L or more and 10 g/L or less, preferably 0.1 g/L ormore and 5.0 g/L or less, and more preferably 0.2 g/L or more and 2.0g/L or less.

The tin electric plating solution of the present invention is adjustedto be in the acidic region. The pH of the plating bath is, for instance,less than 7, preferably 3 or lower, and more preferably 1 or lower. Ifnecessary, commonly known additives such as pH adjusting agents,glossing agents, smoothing agents, conduction agents, anode dissolvingagents, or the like, may also be added to the present invention.

The method of electroplating using the plating solution of the presentinvention may be a commonly known method. Methods such as barrelplating, through hole plating, rack plating, high-speed continuousplating, and the like, are compatible, and the concentration of eachcomponent in the plating solution may be selected arbitrarily. Theelectroplating method which uses the plating solution of the presentinvention may be performed at a plating bath temperature of between 10°C. and 65° C., preferably between room temperature and 50° C.Furthermore, the cathode current density is appropriately selected froma range of, for instance, 0.01 and 100 A/dm², preferably between 0.05and 70 A/dm². During the plating process, the plating bath may be leftunstirred, or a method such as stirring with a stirrer, or the like, orstreaming, or the like, with a pump can be performed.

Embodiments of the present invention will be presented below, but thepresent invention is not restricted to these examples.

EMBODIMENT 1

The additive (A) of the present invention was prepared as shown below.

200 g of 1,2-propylene glycol (concentration 99%) was placed in a 1 Lglass container and then 5 mL of methanesulfonic acid aqueous solution(concentration 70%) was added. The entire glass container was heatedusing a 50° C. water bath and the acidic propylene glycol solution wasstirred until the temperature reached 40° C. While stirring thepropylene glycol solution, 250 g of a 50% concentration glutaraldehydeaqueous solution was added and the solution was stirred for one hourwhile maintaining the temperature between 40° C. and 50° C. The solutionthat was clear became cloudy because of the addition of theglutaraldehyde aqueous solution. The solution that was obtained wascooled to 25° C., and then 240 g of a nonionic surfactant (product name:Adekatol™ PC-8 surfactant) was added while stirring the solution. Thesolution that was obtained was clear. The solution obtained was stirredfor 5 minutes, and then 300 g of polyoxyethylenediamine compound(product name: JEFFAMINE™ XTJ-500) was added to the solution whilestirring. The appearance of the solution was yellow and the temperaturewas 37° C. Stirring was continued until the appearance of the solutionchanged from a yellow to a clear brown color, and then 82 mL ofdeionized water was added and the solution was made to be 1 L. Thesolution that was obtained was cooled to room temperature (25° C.) byallowing to sit. Additive solution A with a brown appearance and a pH of10.6 was obtained.

COMPARATIVE EXAMPLE 1 Reaction System when a Hydrocarbon CompoundContaining a Hydroxyl Group is Not Used

200 g of deionized water was placed in a 1 L glass container, and theentire container was heated using a 50° C. water bath, and then 250 g ofa 50% concentration of glutaraldehyde was added while stirring. 240 g ofa nonionic surfactant (product name: Adekatol™ PC-8 surfactant) wasadded while stirring the solution. The solution that was obtained wascolorless and clear. The solution obtained was stirred for 5 minutes,and then 300 g of polyoxyethylenediamine compound (product name:JEFFAMINE™ XTJ-500) was added to the solution while stirring. Thesolution that was obtained was cooled to room temperature (25° C.) byallowing to sit. A brown gel similar to silicon rubber was obtained.

COMPARATIVE EXAMPLE 2

Additive solution B was obtained by the same method as Embodiment 1,except that 130 g of 85% concentration acetoaldehyde was added in placeof the glutaraldehyde.

COMPARATIVE EXAMPLE 3

Additive solution C was obtained by the same method as Embodiment 1,except that 186 g of a 97% concentration butylaldehyde was added inplace of the glutaraldehyde.

COMPARATIVE EXAMPLE 4

Additive solution D was obtained by the same method as Embodiment 1,except that 274 g of a 97% concentration benzaldehyde was added in placeof the glutaraldehyde.

COMPARATIVE EXAMPLE 5

Additive solution E was obtained by the same method as Embodiment 1,except that 350 g of a 97% concentration anisaldehyde was added in placeof the glutaraldehyde.

EMBODIMENT 2

Additive solution F was obtained by the same method as Embodiment 1,except that 245 g of ethanol (99.5% concentration) was added in place ofthe 1,2-propylene glycol.

EMBODIMENT 3

Additive solution G was obtained by the same method as Embodiment 1,except that 162 g of glycerin (99% concentration) was added in place ofthe 1,2-propylene glycol.

EMBODIMENT 4

Additive solution H was obtained by the same method as Embodiment 1,except that 360 g of glucose (98% concentration) was added in place ofthe 1,2-propylene glycol.

EMBODIMENT 5

Additive solution I was obtained by the same method as Embodiment 1,except that 367 g of sorbitol (97% concentration) was added in place ofthe 1,2-propylene glycol.

EMBODIMENT 6

Additive solution J was obtained by the same method as Embodiment 1,except that 164 g of ethylene glycol (99% concentration) was added inplace of the 1,2-propylene glycol.

Adhesion Ratio Test

A tin plating solution was made from the following composition.

TABLE 1 Stannous methanesulfonate 31.2 g/L (12 g/L as tin)methanesulfonic acid 71 g/L catechol 0.5 g/L Additive solution shown inTable 1 10 mL/L Deionized water remainder pH <1

Using the tin plating solution that was obtained, barrel plating wasperformed on the electrode region of resistors which are chip componentsat a temperature of 20° C. for 90 minutes at 0.1 A/dm². The electroderegion of the chips had previously been coated with a 5 μm thick nickelfilm using nickel electroplating, water washed, and then theaforementioned tin plating was performed. The chip components which hadbeen nickel plated were acid washed for five minutes using a 5%concentration of methanesulfonic acid aqueous solution (solutiontemperature 40° C.), water washed, neutralized by immersing for fiveminutes in a trisodium phosphate aqueous solution (50 g/L) at a solutiontemperature of 50° C., again water washed, and then dried.

The mutual adhesion of the chip components obtained was evaluated as theadhering rate based on the ratio of chip components which had adheredtogether from the total number of chip components. The aforementionedplating solution was made immediately after preparing the additive,three days after preparing the additive, and after allowing the additiveto sit for one week after preparation, and the evaluation results areshown in Table 2. It is thought that the additive reaction product whichis the active ingredient had decomposed in those samples where theadhering rate exceeded 20%, and subsequent evaluation was not performed.The appearance of the tin plating film that was obtained was alsoevaluated. The results are shown in Table 2. In all cases a uniform andsemiglossy appearance was obtained.

TABLE 2 Immediately after 3 days after One week after Additivepreparation preparation preparation Appearance A Embodiment 1 1% or less1% or less 1% or less Uniform, semiglossy F Embodiment 2 1% or less 20%or more Not measured Uniform, semiglossy G Embodiment 3 1% or less 20%or more Not measured Uniform, semiglossy H Embodiment 4 1% or less 20%or more Not measured Uniform, semiglossy I Embodiment 5 1% or less 20%or more Not measured Uniform, semiglossy J Embodiment 6 1% or less 1% orless 1% or less Uniform, semiglossy NONE Comparative Example 1 20% ormore Not measured Not measured Uniform, semiglossy B Comparative Example2 20% or more Not measured Not measured Uniform, semiglossy CComparative Example 3 20% or more Not measured Not measured Uniform,semiglossy D Comparative Example 4 20% or more Not measured Not measuredUniform, semiglossy E Comparative Example 5 20% or more Not measured Notmeasured Uniform, semiglossy

From the above results, it was determined that significantly superiorresults could be obtained by using glutaraldehyde as compared to otheraldehydes. Furthermore, with regards to the alcohol that reacts with theglutaraldehyde, an effect was observed even when a monoalcohol orglycerin was used, but the effect was maintained for a significantlylonger period of time by using a glycol.

COMPARATIVE EXAMPLE 6

3.2 g of the reaction products of glutaraldehyde and 1,2-propyleneglycol prepared for Embodiment 1, 2.4 g of nonionic surfactant (productname: Adekatol™ PC-8 surfactant) and 3 g of a polyoxyethylenediaminecompound (product name: JEFFAMINE™ XTJ-500) were individually added asthe additive to a tin plating solution containing 31.2 g/L of stannousmethanesulfonate, 71 g/L of methanesulfonic acid, and 0.5 g/L ofcatechol, and the adhering ratio was evaluated as shown above. Theresults show that the adhering ratio immediately after preparation was20% or more, and there was no improvement observed in the adhering rate.

COMPARATIVE EXAMPLE 7

Using the same method as the aforementioned adhering rate test,glutaraldehyde, 1,2-propylene glycol, nonionic surfactant (product name:Adekatol™ PC-8 surfactant) and polyoxyethylenediamine compound (productname: JEFFAMINE™ XTJ-500) at essentially the same ratio as was includedin the additive solution of Embodiment 1 to make a total of 10 g wereindividually added to a tin plating solution in place of the additivesolution, and the adhering rate was evaluated. The results show that theadhering ratio was 20% or more and there was no improvement observed inthe adhering rate.

EMBODIMENT 7 Solderability Test

2 L of a tin plating solution that contains the additive of Embodiment 1was prepared, and tin plating was performed for 90 minutes at 0.1 A/dm2while stirring using a barrel at a solution temperature of 20° C. onchip components that had a nickel plating film on the electrode region.The tin plating film obtained was subjected to a humidity resistancetest at 105° C., 100% humidity, for 4 hours (PCT treatment 105° C.,relative humidity 100%, 4 hours), and the solderability of the tinplating film after the humidity resistance test was determined bymeasuring and evaluating the zero cross time by the meniscograph methodusing a solder checker. The measurement conditions were as shown below.The solderability obtained at the following measurement conditions was2.5 seconds.

TABLE 3 Zero cross time measurement conditions Tester:Multi-Solderability Tester SWET-2100 (manufactured by Tarutin Kester)Measurement mode: Paste Quick Mode Solder paste: Sn/Ag/Bi/Cu =96.0/0.5/1.0/0.5 Bath temperature: 245° C. Immersion depth: 0.25 mmImmersion speed: 2.0 mm/second Retention time: 10 seconds Afterheat: 8seconds

What is claimed is:
 1. A manufacturing method for an additive for a tinor tin alloy electroplating solution, comprising: (1) a reaction productcomprising reacting glutaraldehyde with at least one hydroxyl groupcontaining compound in the presence of an acid in a reaction solution toform the reaction product; and (2) reacting at least one amine compoundwith the reaction product in the reaction solution to form the additive.2. The manufacturing method of claim 1, wherein the amine compound has aformula:X₁—CH(X₂)—R—O—CH(Y₁)—NH₂  (I) wherein X₁ is a hydrogen atom or aminogroup, X₂ is a hydrogen atom or a C₁-C₃ alkyl group or an amino group,Y₁ is a hydrogen atom or C₁-C₃ alkyl group or an amino group and R is apolyoxyalkyl group.
 3. The manufacturing method of claim 2, wherein R is—O—CH₂—, —O—CH₂—CH₂—, —O—CH(CH₃)—, —O—(CH₂)₃—, —O—CH(CH₃)—CH₂— or—CH₂—CH(CH₃)—.
 4. The manufacturing method of claim 1, wherein the atleast one hydrogen compound containing a hydroxyl group is chosen frommonohydric alcohol, polyhydric alcohol and a sugar.
 5. The manufacturingmethod of claim 4, wherein the monohydric alcohol is chosen frommethanol, ethanol, propanol, isopropanol and phenol.
 6. Themanufacturing method of claim 4, wherein the polyhydric alcohol ischosen from glycol compounds.
 7. The manufacturing method of claim 6,wherein the glycol compounds are chosen from ethylene glycol,1,3-propylene glycol, 1,2-propylene glycol, 1,2-butylene glycol,1,3-butylene glycol, 1,4-butylene glycol, 1,2-isobutylene glycol and1,3-isobutylene glycol.